A processing apparatus, which is configured to perform a film deposition process to a substrate such as a semiconductor wafer in the course of manufacturing a semiconductor device, includes a substrate table for placing thereon the substrate in a chamber. The substrate is processed while the substrate is supported by the substrate table. In order to heat the substrate depending on process conditions, the substrate table incorporates a heater. For example, when a film deposition process by a thermal CVD method is performed, a temperature of the substrate table is heated by the heater to about 500° C. to 700° C. (for example, 3P2006-283173A).
However, there is a possibility that the substrate may float up from a table surface because of a foreign matter having entered into a space between the substrate table and the substrate and/or that the substrate may be placed on the substrate table at a displaced position that is deviated from a normal position because of a malfunction of a transfer apparatus. In this case, a problem may occur in that thermal conductivity from the substrate table to the substrate becomes non-uniform, so that a process result (for example, film thickness in a film deposition process) becomes non-uniform in a plane of the substrate. In addition, the same problem may occur, when the substrate itself warps so that the substrate partially floats up, and/or when the substrate table itself has a trouble such as deformation or damage so that the substrate is not normally placed.
When the substrate is abnormally placed because of a foreign matter, displacement, trouble of the substrate, or trouble of the substrate table, there has conventionally no method that is capable of detecting the abnormal placement of the substrate during the process. Thus, in almost all cases, a cause for a defective lot or a defective product is searched after the process, and the defectiveness is attributed to the abnormal placement of the wafer. Thus, once the abnormal placement occurs, the defective lots and the defective products are consecutively manufactured, which impairs a throughput.